Photo-electric weft detector for shifting shuttle boxes



l I VHP Inventor Richard reenlea Turner 47! ttorn R. G. TURNER Dec. 3l, 1935.

PHOTO ELECTRIC WEFT DETECTOR FOR SHIFTING SHUTTLE BOXES Filed March 11, 1935 x mnd @mam a Patented 31, 1935 UNITED STATES PATENT OFFICE aozaus v PHOTO-ELECTRIC WEFT DETECTOR FOR SHIFTING SHUTTLE BOXES setta Application Maren 11, 1935, serial No. 10,429

12 Claims.

This invention relates to improvements in weft detecting mechanisms for looms 'having shifting shuttle boxes and it is the vgeneral object of the invention to provide a very delicate detector to be used at the shifting shuttle box side of the loom.

In certain classes of looms shifting shuttle boxes are located on both sides 'of the lay for the purpose of permitting a shuttle to lay a single pick of filling and then pass out of action. These looms, commonly known as pick and pick looms, are likely to have the pattern mechanism so constructed that the shifting boxes will move at both ends of the lay each beat of the loom, and under these conditions it is a dlmcult matter'to detect the condition of weft. I am aware that it has been proposed heretofore to employ various types of detectors both electrical and mechanical to determine the condition of a shuttle -located in the shifting boxes, but so far as I am aware these detectors have not proved satisfactory and because of the manner of their control they are likely to have a harsh action on the weft. In such a loom an active shuttle will be moved' relatively to the lay either through the shed or by a vertical motion in the boxes and there is practically no time at which the active shuttle is at rest with respect to the lay. With the present tendency to increase the speed of looms the rate at which the boxes shift is more rapid than formerly and any period during which the shuttle may be momentarily at rest with respect to the lay is correspondingly reduced. 'I'he problem of detecting is further complicated when the weft is delicate.

I have heretofore proposed the use of a photoelectric weft detector capable of actuation by a change in illumination to be indicated by substantial exhaustion of weft in the shuttle, A detector of this type has no physical contact with the weft being woven and for this reason there is practically no limit on the smallness of the size of yarn which can be'operated with such a detector. It is an important object of my present invention to use a photo-electric weft detector in connection with shifting shuttle boxeo and control the time during which it may operate so that it will be effective so far as any change of illumination is concerned by the shuttle which is next to become active.

The active shuttle is ordinarily boxed in one or another of the cells of the shifting boxes as the lay reaches the point of protection in its forward motion. This point may be located behind the extreme forward position of the lay by an amount equal to one and one-half times the width of the shuttle. The shift of the boxes begins approximately at the protection point and is not completed until the lay reaches so-called top center, or its mid position on the backward stroke. is to be a shift from cell 1 to cell 4 the shift will be approximately half completed when the lay is at front center, but at this time cell 4 is not yet opposite the race and therefore is not in proper position for detection. It is only as the l0 shift nears completion with the lay approaching top center position that cell 4 will come within the range of the detector. It is a further object of my invention to provide means for disabling the detecting unit until the lay has reached such lo l a position that the box which is next to become active is near enough to its picking position to permit correct coaction with the detector. As shown hereinafter I accomplish this control by means of a shutter which blocks of! the actuating 2i?! beam of light until the boxes have almost completed their shift, but I do not wish to be limited to this particular control inasmuch as any means which prevents the detector from completing an indication prior to the specified time will sulce. E.

I prefer to have the detecting unit and also the source of light stationary so that these elements will not be disturbed by the vibration of the lay.

Where the photo-electric feeler is actuated by reected light it is desirable that light from the 3Q source enter the shuttle obliquely so that it can be reflected toward the detector cell along a different path, thereby permitting the cell to be shielded from the source. I have found it convenient to arrange the source and cell so that Sii,A

the plane dened by the incident and reflected rays is more or less parallel to the plane of motion of the lay, that is, substantially horizontal. If the shuttle should lbe in extreme rear position the reflected beam will lie to one side of the 40 times during each beat of the loom when the reflected ray may shine on the sensitive cell,V once when the lay reaches the point in its forward motion, and again when the lay reaches the same point in its backward motion.

In a Shifting* shuttle box loom the boxes will In a four-cell box motion where there gil Athe active shuttle.

2. bain one position when the lay reaches 'thev aforesaid point in its forward beat and the boxes wil1` is to become active, but the shuttle which reaches reflecting position when the lay is at the aforesaid point on its backward stroke is likely to be It is a further object of my invention to provide generally for means which will render the detecting system incapable of giving an indication during the forward beat of the lay, provision being made however for rendering the detector operative during the backward beat thereof' so that upon reaching the aforesaid critical point an empty shuttle can direct a reflected ray toward the detector.

Since the shift of the boxes which is to render a shuttle active may be either up or down with respect to the lay, it is preferable to have the source of light and sensitive cell located in a neutral position where it is effective whether the boxes shift up to render a shuttle active or whether they shift down for that purpose. I nd it ordinarily convenient to have the detecting parts substantially in line with an active shuttle opposite the race and rely upon reection from a cylindrical surface carried by the shuttle to direct a reflected ray upwardly when the boxes are rising to render a shuttle active, and to direct the reflected ray downwardly when the boxes are moving down to render a shuttle active.

With these and other objects in view which will appear as the description proceeds, my invention resides in the combination and arrangement of parts hereinafter described and set forth in the claims.

In the accompanying drawing, wherein a convenient embodiment of my invention is set forth,

Fig. l is an end elevation of a portion of a loom partly in section showing my present invention applied thereto, v

Fig. 2 is a plan view partly in section taken in the direction of arrow 2, Fig. 1, on an enlarged scale,

i Fig. 3 is a rear elevation of the detector unit looking in the direction of arrows 3, Fig. 1,

Fig. 4 is a detailed horizontal section on line 4-4 of Fig. 3,

Fig. 5 is a diagrammatic view showing the way in which the reected beam of light travels relatively to the sensitive cell, and

Fig. 6 is a diagrammatic view showing the relation of the box shift both up and down with respect to the neutral position of the detecting system.

Referring to the drawing, the loom frame III supports a top or crank shaft II which has one revolution for each pick or beat of the loom and is attached by means of connector I2 to a' lay I3. A gang of shuttle boxes I4 is mounted on the upper end of a box lifter rod I5 which is raised and lowered in the present instance by means of a chain actuator I6. The boxes are guided in well-known manner not shown and are subject to control by a pattern mechanism of any approved form not illustrated in the drawing. T'he lay has a shuttle race I1 and the boxes are'movable so that each of them can become actively related to the shuttle race at the time ofpicking. I have shown herein four cells or boxes in the structure I4 designated at I8, I8, 20. and 2|, respectively. The shuttles S in these boxes are retained by binders 22 and the lay 5 end 23 has a slot 24 to receive a pickernot shown but slidable along the picking spindle 2li.

Each shuttle is provided with a weft carrier 30 having a reecting surface 3l normally covered by weft but uncovered as weft exhaustion approaches. 'I'his surface may be carried by a chromium plated metallic ferrule and is located to register with a slot 32 formed in the front wall 33 of the shuttle.

In theoperation of the loom rotation of the crank shaft will act through crank 28 to rock the lay between its extreme front and back positions. When the lay reaches approximately its mid or so-called top center position on the backward stroke thereof the shuttle aligned with the 0,

race Il will be picked to the opposite side of the loom. A picked shuttle is in flight approximately one-half a revolution or beat of the loom and ordinarily enters the box opposite the shuttle race when the lay has reached a point slightly in front of its mid position on the forward beat thereof, whereupon the boxes begin to shift. The boxes will continue to shift while the lay is in forward position and until it reaches approximately its top center, position. This interval of shift is approximately the same for any degree of shift, that is, whether the box movement is for a space equal to 1, 2 or 3 cells of a gang of boxes. The matter thus far described is of common construction and may operate in the usual 35 manner.

In carrying my present invention into effect I provide a detecting unitl comprising two elements one of which constitutes a sou'rce of light and the other of which is a light sensitive cell. As shown in Figs. 1 and 2, I extend from the loom frame a bracket 40 to which a support 4I is secured by means of the bolt and slot adjustment shown at 42 in Fig. 1, thus affording vertical adjustment for the support 4I. The light source or sending 45 element 43 is secured as indicated in Figs. 2 and 3 to the support 4I and has a rearwardly projecting tube 44 from which issues light emanating from the laments 45, see Fig. 4. The sensitive cell or receiving element 46 of the detector unit 5o is also mounted on the support 4I and has a tube 41 extending rearwardly. 'Ihe tubes 44 and 41 are preferably inclined toward each other by the same angular amount having reference to the axis of the shuttle S and the slot 32 and reecting 55 surface 3| of the shuttle are so related that with the lay in certain positions the light issuing from tube 44 will impinge upon the surface 3| and be reflected back through the tube 41 to set up a reaction in the filament 48 of the element 46. By 60 means not shown herein but set forth more particularly in my co-pending application Serial No. 720,739 means are provided for eecting a change in the operation of the loom whenever a light beam is reflected from the surface 3i onto the 65 filament 48. The elements 43 and 46 are ordinarily fixed with respect to each other, although I provision is made for varying the distance between them as by the bolt and slot connection designated generally at 49. It will be understood that the axes of the tubes 44 and 4l when extended rearwardly will intersect at a point from which a beam originating in the light source can be reflected to the sensitive cell. The location of this point can be varied by adjustment of the elements of the detector unit with respect to each other.

The relation of the reflected beam with respect to the sensitive cell is set forth diagrammatically in Fig. 5, where the rearmost position of the reilecting ferrule with the lay on back center is indicated in dot and dash lines at a and in extreme forward position at the dotted line b. The full line c indicates an intermediate point between the extreme positions of the lay at which the shifting of the boxes has become so near complete that detection can take place.

Light starting from the source 4I and projected obliquely against the reflecting ferrule when in the position a in Fig. 5 will be reflected along line d which lies to the right of the sensitive cell I6. As the lay moves forwardly the reflecting ferrule will assume the position shown at the full line c, in which position the reflected light will follow the line e and be directed toward the sensitive cell 46 to actuate the latter. As the lay continues to move forwardly to the dotted line position, the reflected beam moves to the left of the sensitive cell and travels along the line f. It will be seen therefore that as the -lay moves forwardly there is one particular position where conditions are most favorable for excitation of the sensitive cell by a reected beam of light.

When'the lay moves from its forward position backwardly the reflected beam travels in the reverse direction and will again follow the line e when the reilecting surface is located to correspond to the solid line c of Fig. 5, after which continued backward movement of the lay will move the reflected beam to the right of the sensitive cell. It is apparent, therefore, that for each forward and backward motion of the lay there will be two points in the cycle of loom operations when a reected beam can fall on the sensitive element 46.

The box shift begins when the reflecting sur` face reaches a position corresponding approximately to line c of Fig. 5 during the forward motion of the lay. At this time in the loom operation it is inconvenient to determine so far as the light beams are concerned which of the shuttle boxes will be rendered active by the box shift and I therefore arrange by means to be described hereinafter to prevent operation of the detecting unit during the first part of the box shift. After the lay has reached front center position and starts to move rearwardly, however, it will assume a position where the box shift is so nearly complete that detection can safely be effected and the aforesaid mechanism to be described is so controlled as to permit a detecting operation during the backward stroke of the lay.

While I have shown a particular relation between the source of light and the sensitive cell with respect to movements of the reflecting surface in Fig. 5, yet I do not wish to be limited so far as all features of my invention are concerned to the use of a light source which Will necessarily act as indicated in that figure.

Referring' more particularly to Fig. l, I secure to the crank shaft a cam 60 having a high dwell 6I and a low dwell 62 which co-act with the rear end 63 of a lever 6I pivoted as at 65 to the loomside. A spring 66 may act if desired to hold the lever in operative relation with respect to the cam and assist gravity in depressing the forward end 61 of the lever. Extending upwardly from end 61 of the lever is a rod B8 having pivotal connection as at 69 to a shuttle or light shield 10 having a light intercepting wing Il capable when properly positioned to prevent light which issues from the tube from traveling toward the boxes. The shield 10 is pivoted as at 12 on a stud which is carried by a stand 1l mounted on the bracket I0.

The time of operation of the lever Il is such 5 that the high dwell 8| will act to hold the shield in light blocking position relatively to the source of light during the greater part of the pick of the loom, and particularly during the forward beat of the lay. As the lay starts to move rearwardly 10 and reaches such a position as will place the shuttle next to be active very close to active position relatively to the shuttle race the cam will permit a rocking of the lever 64 under the action of the spring 66 by presenting the low dwell 62 to 15 the rear end of the lever. At this time the shield will drop from the full to the dotted line position shown in Fig. 3 andl light can travel rearwardly from the tube M. If the beam of light should fall upon a mass of yarn, insufficient light will be reected toward the sensitive cell and the latter will not be excited, but if the supply of weft in the shuttle almost in picking position has become depleted so as to uncover the reflecting ferrule 3|, then light will be reflected in sumcient 25 amount to actuate the sensitive cell and bring about a change in loom operation as already stated.

When moving to active position the inner shuttle boxes I9 and 20 may move either up or 30 down depending upon the previous position of the gang of boxes I4. If the boxes have been raised the shift will be down, but if vthe boxes had previously been down, the shift will be up. In either character of shift it is desirable to get a reflected beam from an uncovered ferrule 3| to the sensitive element a short time before the shuttle next to be active actually reaches active position.

In order to render the detector equally eiective for both up and down shifts of the boxes the binders and shuttles are provided with slots of suflicient width to permit reflection of light when an uncovered ferrule is slightly above or slightly below the picking position. As shown diagrammatically in Fig. 6 the beam of light will start from the source 43 when permitted to do so by lowering of the shield 10 and will travel along the rearwardly and downwardly inclined path indicated by dotted line g as well as along the rearwardly and upwardly inclined path designated at the dot and dash line h. In other words the beam of light will be of sufllcient height to illuminate the ferrules in shuttles above and below the picking position.

The binder of each box will have a slot l0 of such width that when an uncovered ferrule 3| is in the low dotted position shown at j, Fig. 6, a beam of light can start from the source, pass through the upper part of the slot 80, implnge upon the ferrule 3| and be returned in the plane indicated by the dotted line g. When an uncovered ferrule is in the upper dotted and dash line position indicated at k in Fig. 6 and is moving downwardly, a beam of light moving along the line I will be able to pass through the lower part of the slot 80 and be reected back to the sensitive cell.

It is believed that the operation of the weft detector will be understood from the foregoing description. As set forth herein the elements of the detector unit may both be stationary while the lay moves back and forth and the boxes shift vertically. With a suiliciently narrow band oi' light the relation set up in Fig. 5 can be relied 15 upon to effect indication through the detector when the lay reaches a denite position on its rear stroke, but as already stated I do not wish to be limited 4to such a narrow band of light, in-

l'indicate the condition of. weft in any of the cells without actual ptwsical engagementv with 4the weft carried in the several shuttles. The shield 1I acts to prevent a beam of light from falling on the cell I6 until that point is reached in the shift oi' the boxes when the shuttle next to be active approaches active position.- While I have shown this particular means for disabling the detecting unit at all times except that at whichv detection can be effected, yet I do not wish to be limited to the interruption of light as the only means for eiiecting its control. It will further be seen that provision is made lfor detecting "a vertically moving shuttle whether descending or ascending in its motion toward active position.

Having thus described my invention it will b e seen that changes and modifications may be made therein by those skilled in the art without departing from the spirit and scope of the in,

vention and I do not wish to be limited to the v details herein disclosed, but what I claim is:

1. In a loom', a lay, shifting shuttle boxes any one of which may become active with respect lto the lay, a photo-electric weft detector effective when subjected to an actuating change in illumination to indicate weft exhaustion, a xed source of light to actuate the detector, and means acting in timed relation with the shifting of the shuttle boxes to prevent the source of light from directing a beam of light toward any shuttle box exceptthe one next to be active. Y.,

2. In a loom, a lay, a plurality of shuttle boxes each to become active with respect to the` lay and shiftable during a given period in the cycle of loom operations, a photo-electric weft detector effective when subjected to an actuating change in illumination to indicate weit exhaustion, a source of light capable during shifting of the boxes to illuminate any shuttle box near active position, means carried by each shuttle box efiective at weft exhaustion to direct a beam of light received from the source of light toward the weft detector, and means to prevent the source of light from illuminating a shuttle box adjacent active position until the latter part of said period'in the cycle of loom operations.

3. In a loom, a lay, shifting shuttle boxes movable relatively to the lay .when the latter is in the forward part of its motion, a photo-electric detector element, a light source element, one of said elements being stationary, the lay movable toward and from the stationary element, a light reilector'carried by each shuttle box to be positioned during the forward and backward movement of the lay to direct a beam of light from the source element to the detector element, depending upon the position of the boxes, and means to prevent the beam oi light from falling on a reflector during the forward movement of the lay and effective during backward movement of the lay to render the beam of light capable -of falling on a reflector.

4. In a loom, a lay movable back and forth, shifting-shuttle boxes carried by the lay, weft carriers to be received by the boxes, a reflector for each carrier, each reflector becoming eective to reect light when the weft of the corresponding carrier is exhausted, a photo-electric weft detector effective when subjected to an actuating beam of light to indicate weft exhaustion, 10 a source of light to cooperate with the reflectors in the boxes and eiective to cause any reflector corresponding to an exhausted carrier to reflect an actuating beam of light toward the detector, and means to shield the light and prevent the same from directing a beam of light toward the reectors until the boxes in their shifting motion reach a predetermined position with respect to the lay. y

5. In a loom, a lay, shifting shuttle boxes movable with respect to the lay so that any box may 'be in picking position, a photo-electric weft detector to indicate weft exhaustion when subjected to an actuating vchange of illumination, a source of light, light reecting means in -each shuttle box rendered effective by substantial exhaustion of weft to reflect an actuating beam of light from the source toward the detector, and means to prevent the beam of light from being directed toward the light reflecting means until the shuttle box next to be active is nearer picking position than any other shuttle box.

6. In a loom, a lay, shifting shuttle boxes each movable to picking position with respect to the lay, shuttles to be received by said boxes, a photoelectric weft detector effective when subjected to an actuating change in illumination to indicate weft exhaustion, a source of light, reflector means carried by each shuttle and effective after boxing'thereof subsequent to the occurrence of sub- 40 stantial exhaustion to cause a light beam received from the source of light to be reflected toward the detector, and means to intercept the beam of light toward any reector means except the one which is to be in active position with respect to the lay.

'1. In a'loom, a lay, shifting shuttle boxes each movable to active position with respect to the lay, shuttles to be received by said boxes, a fixed photo-electric weft detector eiective when subjected to an actuating change in illumination to indicate weft exhaustion, a source of light, a reflector carried b y each shuttle rendered effective upon exhaustion of the corresponding weft to reflect light from the source to the detector to cause an actuating change in the illumination of the detector, and means to prevent the source of light from illuminating any reflector except the one which is carried by the shuttle which is to become active.

8. In a loom, a lay, shifting shuttle boxes any one of which may become active with respect to the lay, shuttles to be received by said boxes, a photo-electric weft detector effective when subjected to an actuating change in illumination thereof to indicate weft exhaustion, a source of light, reflector means carried by each shuttle normally effective after boxing of the shuttle subsequent to the occurrence of substantial vexhaustion to reflect a beam of light received from the source of light toward the detector, and means to interrupt the beam of light during the shifting of the Y boxes until the box next to be active is nearer active position than any other box.

9. In a loom, a lay, shifting shuttle boxes each movable to active position with respect to the lay, shuttles to be received by said boxes, a stationary photo-electric weft detector, a stationary source of light, reflector means carried by each shuttle effective after boxing of the shuttle subsequent to the occurrence of substantial exhaustion to reflect a beam of light from the source toward the detector, and means to render ineffective any of the reiiector means except that carried by the shuttle next to be active.

10. In a loom, a lay, shifting shuttle boxes each movable to active position with respect to the lay, shuttles to be received by said boxes, a stationary photo-electric weft detector, a stationary source of light, reflector means carried by each shuttle to reect a beam of light from the source toward the detector after boxing of a shuttle subsequent to the occurrence of substantial exhaustion therein, and means to prevent the source of light from illuminating any reflector means except the one next to be active.

1l. In a loom, a lay," shifting shuttle boxes movable relatively to the lay when the latter is in the forward part of its motion, a photo-electric weft detector element responsive to a change in illamination, a. source of light, means carried by each shuttle effective upon substantial exhaustion of weft to reect a beam of light from the source to the detector, and an` opaque shield operative while the lay is moving forwardly to intercept and prevent a beam of light from the source from falling on said means and operative during the backward movement of the lay to allow falling of the beam of light from the source on the means.

12. In a loom, a lay, a plurality of shuttle boxes shiftable with respect to the lay during the latter part of the forward and the rst part of the backward movement of said lay, shuttles to be received by said boxes, a photo-electric weft detector element, a light source element, one of said elements being stationary, a reflector carried by each shuttle to be uncovered as weft exhaustion approaches, the lay moving to a position in its forward motion to locate a reflector after boxing of a shuttle subsequent to the occurrence of substantial exhaustion so that the same is capable of reiiecting a beam of light from the 20 

